The Western-style liberal party of the two-metre-tall Klitschko has rocketed up in the ratings and will now enter parliament for the first time.

"Currently, according to exit polls results, we are Ukraine's number three party in terms of voters' support. I think this result is not bad at all for a young party, and I'm sure we'll capitalize on this result and will prove our professionalism and credibility during our work in parliament," Vitaly Klitschko said at his party headquarters late on Sunday.

Ukrainian President Viktor Yanukovich's pro-business party seemed likely to hold on to a majority in parliament after Sunday's election, but it will face a revitalised opposition boosted by Klitschko as well as a resurgent nationalist party, exit polls showed.

Leaders of the Party of the Regions claimed victory after two exit polls put it in the lead with between 28 percent and 30.5 percent of the voting in the part of balloting conducted by party lists.

If the exit polls are proven accurate, Klitschko, the WBC heavyweight boxing champion, will now enter parliament at the head of his new party after a campaign in which he has been critical of corruption and cronyism under Yanukovich's rule.

"If just a few months ago the UDAR party, chaired by a sportsman, by a world champion, led only to people smiling and grinning, then over time those grins have ceased to exist," Klitschko said.

Klitschko, who trained in Germany for much of his boxing career, won 41 of his 45 victories on knockouts and is known as Dr. Ironfist because he holds a doctorate in sports science.

Commentators are already seeing Klitschko - projecting an honest 'big-man' image that sells well in the former Soviet republic - as a potential contender to rival Yanukovich for the presidency at the 2015 presidential election.